Electrical clamp-and-connector



' Jan. 9, 1962 s. BLONDER 3,016,510

ELECTRICAL CLAMP-AND-CONNECTOR Filed July 25, 1958 4 INVENTOR.

flsaac 6. ZIZma er m W M ATTORNEYS United States Patent thee patented Jan. 9, 1962 3,016,510 ELECTRICAL CLAMP-AND-QONNECTQR Isaac S. Blonder, West Grange, N..l., assignor to Blonder- Tongne Electronics, Newark, N.J., a corporation of New Jersey Filed July 23, 1958, Ser. No. 750,489 8 Claims. (Cl. 339-97) The present invention relates to electrical clamp-andconnectors, and, more particularly, to connectors that are adapted to hold and establish electrical contact with insulation-covered transmission line conductors. and the like.

Numerous types of clamps and connectors have been proposed throughout the years for employment with transmission-line conductors and the like. The present invention is particularly directed to providing a new and improved combined clamp-and-connector that neither requires the conventional stripping of the insulation of the transmission line and the like, in order to establish electrical connection, nor soldering or other special connecting steps. The present invention, indeed, embodies a very simple type of clamping structure that not only maintains the transmission line against slippage or movement, but, at the same time, inherently provides electrical connection by penetrating through the insulation of the transmission line or other insulation-covered conductor to establish reliable electrical connection.

A further object of the present invention is to provide such a novel combined clamp-and-connector that permits of facile and rapid application and removal.

Other and further objects will be explained hereinafter, and will be more particularly pointed out in the appended claims.

The invention will now be described in connection with the accompanying drawing, the FIG. lot which is a perspective view illustrating a preferred embodiment of the present invention adapted for use with conventional twoconductor insulation-covered television-type transmission line cable and the like;

FIG. 2 is a fragmentary section, upon an enlarged scale, taken along the line 22 of FIG. -1, looking in the direction of the arrows;

FIG. 3 is a perspective view of the frusto-conical clamping member employed in FIGS. 1 and 2; and

FIG. 4 is a view similar to FIG. 2 of a modification.

Referring to the drawing, the insulatiomcovered transmission line is shown at 1 provided with a pair of spaced substantially parallel conductors 3 and 5 embedded within the insulation 1 along the marginal edges'thereof, as is well known. It is to be understood, of course, as will be more evident from the hereinafter described operation,

that the invention is equally applicable with other types of conductors, also. In accordance with the invention, a pair of threaded binding-post members "i and 9 are threaded through the apertures of respective conductive terminal-strip members 17 and 19,.secured, in turn, at

corresponding apertures 22, FIG. 2, in an insulating base member 21, as of sheet Bakelite and the like. Thus, in FIG. 2, the binding post '7 is illustrated as threaded within aperture 24 in terminal strip member 17, depending below the base member 21. Each of the terminal strips 17 11 and '13 of the binding posts. Part of the conical sur face of each of these frusto-conical members 2 and 4 is serrated upward from the periphery of the respective bases 2 and 4", the serrations extending preferably substantially half-way up along the cone, and, for purposes, later described, being twisted slightly out of the surface of the cone, as illustrated.

if the apertures 24 of the conductive terminal strips 17 and 19 are spaced a distance apart slightly greater than the separation between the conductors 3 and 5 of the transmission line 1, the line 1 may be inserted therebetween, as illustrated. The binding post members '7 and 9 maythen be threaded downward to cause the inner serrations 2 and 4 of the frusto-conica-l members 2 and 4 that are adjacent the transmission line 1 to bear vertically down upon the same. In so doing, the outer portions of the frusto-conical clamping members 2 and 4 may be forced, as at I, FIGS. 1 and 2, against the outermost por lions of the respective clamping strips 17 and 19. The innermost portions of the serrations 2 and 4" of the frusto-conical clamping members 2 and 4, will dig into the insulation 1 between the conductors 3 and 5 with oppositely directed, transversely inward components of clamping force, as a result of the conical shape and the before-mentioned outward twisting of the serrations, as at points ll, FIG. 1. Both vertical and inward clamping forces are thus directed upon the line. The adjacent serration portions 2 and 4 cutting through the insulation "1 immediately above the conductors 3 and 5, as at Ill, will provide reliable electrical engagement therewith. The transmission line 1 is thus mechanically clamped and prevented from both longitudinal and lateral slipping, while, at the same time, being electrically connected with the binding-post members 7 and9 and the extensions 17 and l9'-all without the necessity for stripping the line, establishing solder connections, or involving additional separate clamping and connecting steps.

In order to provide best clamping action, it has bee determined that the diameter of the bases at the ser ration region 2v and 4" of the respective frusto-conical members 2 and 4 should be sufiicient that the innermost serrations dig into the insulation between the conductors 3 and 5 with the before-mentioned inward transverse clamping component as well as, of course, the vertical clamping component. The diameter of the base of the frustoconical members 2, 4, will, accordingly, be larger than the required diameter of the heads 11 and 13 of the binding post members 7 and 9.

If desired, the diameter of the opening at the vertex ends 2' and 4' of the clamping members 2 and 4 may be made somewhat less than the diameter of the threads of the binding posts, as shown in FIG. 4. The clamping members may be assembled prior to forming the threads upon the binding posts to attain this result. The frustoconical clamping members 2 and 4 will then not slip downward as the binding post members 7 and 9 are loosened.

Further modifications will also occur to those skilled in the art, and all such are considered to fall within the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

l. A clamp-and-connector for an insulation covered conductor and the like having, in combination with said insulation covered conductor, a base, a threaded binding post projecting from said base and having an enlargement thereon spaced from said base and movable toward and away from said base-in the direction of the length of said post, and a hollow conductive clamping member mounted upon said bin-ding post, said clamping member being fi'usto-conical with an apex portion adjacent said enlargement and a base portion adjacent said base, said clamping member having a side wall which diverges from said apex portion to said base portion, said diverging side wall having a row of teeth, each of which has its length in the direction of side wall divergence and each of which has a tip at said base portion, said insulation covered conductor being interposed between said base and teeth of said clamping member, whereby when said clamping member is pressed toward said base by said enlargement, the teeth exert upon said insulation covered conductor forces having components parallel to said base as well as perpendicular to said base, and the teeth are pressed into the insulation to make electrical contact with said conductor and to clamp said insulation covered conductor to said base.

2. The invention of claim 1, wherein said teeth are slightly twisted along their length.

3. The invention of claim 1, wherein said clamping member is resilient and wherein the cross-sectional dimension of said base portion is greater than that of said enlargement.

4. The invention of claim 1, wherein said teeth extend substantially half-way from said base portion to said vertex portion along said side wall.

5. The invention of claim 1, wherein said base has an aperture and said binding post is threaded into said aperture.

6. The invention of claim 1, wherein said base is insulating and has an apertured conductive terminal stnip thereon with an extension below said base, and wherein said binding post is conductive and is threaded through the apeitured terminal strip and extends below the base.

a pair of threaded binding posts projecting from one side thereof and spaced apart a distance slightly larger than the spacing of the conductors of the line, each of said binding posts having an enlargement thereon spaced from said base and movable toward and away from said base in the direction of the length of the binding post, and a pair of hollow conductive clamping members, one mounted on each of said binding posts, each of said clamping members being frusto-conical with an apex portion adjacent the associated binding post-enlargement and a base portion adjacent said base, each of said clamping members having a side wall which diverges from said apex portion to said base portion, said diverging side wall having a row of teeth, each of which has its length in the direction of side wall divergence and each of which has a tip at said base portion, said transmission line being interposed between said base and said clamping members with teeth of said clamping members overlying the respective conductors, the diameter of the base portion of each clamping member being sufiicient that when the associated en-. largement is moved toward said base to cause the clamps ing member to clamp the transmission line, the teeth innermost of the line clamp the insulation between the conductors of the line, while the adjacent teeth engage and make electrical contact with a conductor of the line, said teeth exerting upon said transmission line forces having components parallel to said base as well as perpendicularto said base.

References Qited in the file of this patent UNITED STATES PATENTS 1,749,600 Olson Mar. 4, 1930 2,576,906 Poupitch Nov. 27, 1951 2,654,857 Finkel Oct. 6, 1953 2,715,929 Knohl Aug. 23, 1 955 2,859,423 Hyman Nov. 4, 1958 FOREIGN PATENTS 246,263 Great Britain J an. 28, 1926 

